Auditory central gain compensates for changes in cochlear output after prolonged low-level noise exposure.
Auditory central gain compensates for changes in cochlear output after prolonged low-level noise exposure.
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DOI：
10.1016/j.neulet.2018.09.054
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发表时间：
2018-11-20
影响因子：
2.5
通讯作者：
Salvi R
中科院分区：
文献类型：
--
作者：
Sheppard A;Liu X;Ding D;Salvi R
值得注意的是，中枢听觉系统可以根据先前的声学经验来修改其声音诱发的神经反应的强度，这种现象被称为中枢增益。在创伤性噪声暴露后，增益变化有很好的记录，但在长期暴露于低水平噪声后，对中枢增益动态的了解要少得多，这是许多城市和工作环境中常见的声学体验。我们最近报道，耳蜗的神经输出减少，而在下丘（IC）的增益增强后，5周暴露于75分贝的噪声。为了确定在更低的强度下是否存在类似的效果，我们将大鼠暴露于65 dB的噪声中，期望在耳蜗或IC中看到很少或没有变化。暴露对畸变产物耳声发射几乎没有影响，也没有引起任何毛细胞损失。而反映耳蜗神经输出的CAP振幅则降低了50- 75%。令人惊讶的是，来自IC的神经反应增强了70%，主要是在噪声暴露频带内的频率。暴露后一周，CAP振幅恢复正常的频率内或以上的曝光带，而低于曝光带的频率诱发的反应增强了80%以上。相比之下，低于暴露频率的IC响应被抑制10-20%，而暴露频带内的响应被增强10- 20%。因此，中枢听觉系统动态地上调和下调其增益，以将阈上神经反应维持在狭窄的稳态范围内;这一功能可能有助于防止声音被感知为低沉或过于响亮。
Remarkably, the central auditory system can modify the strength of its sound-evoked neural response based on prior acoustic experiences, a phenomenon referred to as central gain. Gain changes are well documented following traumatic noise exposure, but much less is known about central gain dynamics following prolonged exposure to low-level noise, a common acoustic experience in many urban and work environments. We recently reported that the neural output of the cochlea is reduced, while gain was enhanced in the inferior colliculus (IC) following a 5-week exposure to 75 dB noise. To determine if similar effects were present at even lower intensities, we exposed rats to a 65 dB noise expecting to see little to no change in the cochlea or IC. The exposure had little effect on distortion product otoacoustic emissions and did not cause any hair cell loss. However, the amplitude of the CAP, which reflects the neural output of cochlea, was depressed by 50–75%. Surprisingly, neural responses from the IC were enhanced up to 70%, mainly at frequency within the noise exposure band. One-week post-exposure, CAP amplitudes returned to normal at frequencies within or above the exposure band, whereas responses evoked by frequencies below the exposure band were enhanced by more than 80%. In contrast, IC responses below the exposure frequency were depressed 10–20% whereas responses within the exposure frequency band were enhanced 10–20%. Thus, the central auditory system dynamically up- and down-regulates its gain to maintain supra-threshold neural responses within a narrow homeostatic range; a function that likely contributes to the prevention of sounds from being perceived as muffled or too loud.
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DOI：
10.1523/jneurosci.5027-12.2013
发表时间：
2013-03-27
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
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通讯作者：
Liberman MC
影响因子：
3.3
作者：
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通讯作者：
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影响因子：
16.2
作者：
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通讯作者：
Polley DB
DOI：
10.1523/jneurosci.2845-09.2009
发表时间：
2009-11-11
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
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作者：
Kujawa SG;Liberman MC
通讯作者：
Liberman MC
影响因子：
3.4
作者：
Barrigon Morillas, JM;Gomez Escobar, V;Trujillo Carmona, J
通讯作者：
Trujillo Carmona, J